== VULNERABLE dirfs_write transcription (vnops.c:740-755)
  bread failed with EIO but write() returns: 0 (SUCCESS — error swallowed at :741)
  read back target file: STALE DATA FROM ANOTHER FILE present at offset 7000
  => INFO LEAK INTO ATTACKER-READABLE FILE CONFIRMED (CWE-909: uninitialized/stale buffer persisted)

== FIXED dirfs_write transcription
  write() returns: 5 (EIO=5) — failure reported to user, nothing persisted
  read back target file: no stale data => NO LEAK, FIX VALIDATED

RESULT: vulnerable loop persists stale buffer contents and reports success; fixed loop reports EIO and persists nothing => BUG CONFIRMED, FIX VALIDATED
harness exit code: 2 (2 = BUG CONFIRMED + FIX VALIDATED)